A variety of billboard and signboard systems are available for daytime and nighttime outdoor advertising. The McGee U.S. Pat. No. 3,198,066 and the Joss U.S. Pat. No. 2,491,184 describe outdoor advertising billboards convertible to projection screens for nighttime advertising messages. These patent references describe the use of front screen projection on the billboard for moving displays or for changing the displays periodically. The billboards are designed for traditional daytime billboard displays and nighttime use with a screen. A timing mechanism is provided for this purpose. The Cordill et al. U.S. Pat. No. 1,740,499, the Gould U.S. Pat. No. 1,644,580, and the Pierson U.S. Pat. No. 3,069,970 describe billboard and signboard arrangements with rear screen projection for providing animation and for changing the billboard displays.
Each of the foregoing patent references and existing billboard and signboard systems, however, contemplate traditional outdoor advertising billboards, signboards, and related equipment. A disadvantage of such advertising systems is that billboard and signboard advertising has been outlawed in many states along with off-premise advertising signs and billboards generally. No successful advertising medium has been devised as a substitute for such traditional billboard and signboard location advertising.